JoB, Confused about STR8 draws

[StrayBullet]

I've been using Bob Dancer's program to learn Jacks or Better, preparing for my trip to Vegas at the end of September.
 
I ran into something I don't understand regarding draws in 2 VERY similar situations.  I'd rather not blatantly memorize moves, for me it's easier if I understand the "why" behind the move.
 
hand 1
 
Ah 2c Jh Qs Td...suggested move was to hold Ah Jh
 
hand 2
 
Ah 2c Jh Qs Kd...suggested moved was to hold Ah Jh Qs Kd
 
When drawing to the King to fill, the ev move is drawing to royal/flush/str8 but when drawing to a 10 to fill the same straight, it's correct to make that str8 draw....I've been playing cards for several years and have a decent grasp on odds, but this has me confused!

[MikeA]

I'll venture a "logical" suggestion for the strategy decision to hold for the straight.  With the ten in the mix, you have one less card to hit a paying (pushing) pair.  With the four faces, you have one more opportunity to not only hit the straight, but have one more face that will push if you draw it.

[StrayBullet]

That makes sense, thanks!